1. Field of the Invention
The present invention relates to a thermally conductive, electrically insulating composite film, and in particular relates to a stack chip package structure utilizing the same.
2. Description of the Related Art
Heat density is continuously increased with the enhancement of chip efficiency. According to the prediction of ITRS and iNEMI, low cost devices, cost-performance devices, and high performance devices will face serious challenges relating to thermal management of their electronic components. Taking cost-performance devices as an example, their heating density is estimated to be about 85 W/cm2. When the process critical dimension progresses to 14 nm, the device power density will be increased to over 100 W/cm2, and the device junction to ambient will be less than 0.2° C./W, which causes a bottleneck in practical application. Moreover, hot spots create problems as a result of uneven thermal dissipation of the chip. This problem becomes worse as heat accumulates. According to reports from Intel, IBM and Fujitsu, the thermal conductivity of the devices is dramatically enhanced by the hot spots, and it is desirable to reduce the thermal resistance of the thermal dissipation devices by one-third to one-fifth.
Most of the conventional thermal dissipation methods depend on top heat spreaders, wherein the hot spots are evenly dissipated and then removed by coolers. However, the hot spot problems in stack chip package structures are even more severe. Especially when the chips generating heat are stacked in the middle of the stack structure, it is difficult to conduct heat to ambient levels. The accumulated heat will influence the periphery chips and reduce the devices' reliability.
Accordingly, the need exists for a novel thermal conductive structure which will improve thermal conductivity without changing the current production process and driving up costs.